Field of the Invention
The present invention relates to a sheet discharge device, an image forming system, and a sheet post-processing device and, more particularly, to a sheet discharge device provided with a first tray on which sheets are stacked and a sheet bundle forming unit that forms a sheet bundle on the first tray, an image forming system provided with an image forming unit that forms an image on each sheet and a sheet conveying unit, and a sheet post-processing device provided with a processing tray on which sheets are temporarily stacked and a sheet bundle forming unit that forms a sheet bundle on the processing tray.
Description of the Related Art
In the field of an image forming system, there are widely known a sheet discharge device and a sheet post-processing device (finisher) that form a sheet bundle on a stack tray (discharge tray). The device of such a type performs jog sorting as needed when forming sheet bundles on the stack tray without applying binding processing thereto to stack the sheet bundles such that they are offset to one another.
In the jog sorting mode, sheets are discharged one by one onto the stack tray, and then the entire stack tray is moved in a direction crossing a sheet conveying direction every time sheets constituting one sheet bundle are discharged. However, a high torque motor is required in order to move the entire stack tray in the jog sorting mode.
Thus, for example, Patent Document 1 discloses a technology in which when a sheet bundle is formed on a stack tray, a processing tray is used to divide sheets constituting one sheet bundle into a plurality of sets and discharged a plurality of times for each set. Specifically, when the number of sheets is 14, the sheets are divided into sets of 5 (sheets)-5 (sheets)-4 (sheets) for discharge. This technology is advantageous in that aligning property of a sheet bundle stacked on the stack tray is improved and that a high torque motor for moving the entire stack tray is not required.